Fruit drier



.April 13 1926.

` 3. R. ANDERSON FRUIT DRIER Filed August 5 NVENTOR ATTOR EYE X'Patented pr. 13, 1926. n

QUNlTl-:D STATES PATENT oFF-lcs.v

` GEORGE B. ANDERSON, 0F SANTA ROSA, CALIFORNIA.

FRUIT DRIER.

l, application' mea Auguste, 1925. 'serai no. 47,705.

To all-whom# may concern:

Be it known that I, GEORGE R. ANDERSON,

a citizen of the United States, residing aty generally lmprove and simplify the present operation of drlers of the character delscribed, to provide a simple, easily operated mechanism wherebyv the inflow and exhaust of air may be regulated, and further to pro! vide a' pre-heater whereby the Aincoming air may be heated by the exhausting airin such a manner as to gainthe greatest heat eli-iciency possible. v

One form which my invention may assume is exemplified' in the following description vand illustrated inthe accompanying drawing in whichl v Fig. 1 is a side elevation of the drier showing the application ofthe pre-heater.

Fig. 2 is a cross section of the drier taken on line II-IIof Fig. 1.l v

Referringv tothe drawings in detail and particularly to Figs. 1 and 2, it will be seen that lthe drierv consists of two inter-spaced side walls as' indicated at Avand B. These side wallsare Vconnected or tied together by end walls 2-2, a roof 3, and an interior floor 4 which lis 'preferably constructed of concrete or the like to present a smooth sur. face. The' interior of the drier 'is divided longitudinally into two\ main compartments by a central partition/wall 5, and each conf partment is 1n turn divided into an upper and a lowerl compartment. as shownA atv .and .D vby means of a floor section 4 the function ofwhich will hereinafter be described. y formed by vthe central parti-tion wall 5 are identical inform and construe-tion, and a description of' one'should therefore sutlice. Mounted in the upper compartment is a steam radiator 6, and `disposed in front 4is also provided with a pair VThe two lmain' compartments' thereof is a fan or blower 7. There are two steam radiators in each upper compartment, and similarly two blowers. A shaft extending longitudinally in the housing is connected with` each blower and the shaft.

is in turn connected with the drivingmotor 8 so that all the blowers may be driven and operated in unison.

through means of a pipe 6l and the condensate is removed. througha pipe 9. A thermostat actuated valve 10 regulates the iow of steam to each radiator, and a thermostat re u'lator 11 mounted on the side of the buildlng is employed to regulate the Steam is delivered to. the radiators fronr any suitable sourcethermostat valves;l that is, each radiator is provided with a thermostat actuated valve 10 and each valve is in iturn connected with a thermostat regulator so that the flow of steam through each radiator' may be regu lated and automatically controlled. Each main compartment isalso provided with a hygrometer .as indicated at 12. These hygrometers are placed onl the interior wall of the building in front of windows l13 from wherethey can. be observed whenever desired. Each upper compartment is provided 'with a pair of air inlet pipes as indicated at 14. These inlet pipes arel vertically disposed on the -rear side of the building and they are all connected with a common an! inlet pipe which is horizontallyvdisposed as shown at 15. Each'upper compartment D 16. These pipes are incommunication with the lower compartments vertically upwardly into the inlet pipes 14 and then extend downwardly through the same, exhaust pipe the suction side of the blower 18.

17 which is connected with The main exhaust pipe 17` extends-through' thema-in inlet pipe 15. It is interspaced with rela- C ,tion thereto 'to form an annular air inlet the pipesl .which ein1 passage and so are tend through the vertically disposed inlet of exhaust LIC. VThey extend and are finally connected with a main Y.

pipes 14. The specific exhaust pipes 16 are each provided with a damper 19 and these are regulated by hand levers on the Aexterior of the pipes as shown at 20.'` The floor section 1P which divides the main compartments lnto upper and lower compartments as shown at C and D are provided with openings as yindicated at 21 and 22. These openings permit a continuous circulation of the air between the `upper and lower compartments as indicated by the arrows; that is, the

blowers `7 discharge the air forwardly through the steam radiators 6 in the direction of arrow a, the air then passes downwardly-through the opening 21 and through the compartment C, and is then directed outwardly through the opening 22 where it" C a series of loading platforms such as indicated at 25 are employed rlhese platforms are handled by a special form of truck which may be passed under the platform to raise the same and support it when a load is to be moved from place to place.

The truck is similarly capable of being lowered to release the platform when a load has reached its destination. To appreciate this feature, it may be supposed that prunes are being dried. Prunes require considerable handling and transferring from place to place, and the trucks are therefore exceedingly useful. It is iirst necessary to Vdip the prunes in a lie solution to .slightly crack the peel or skin as this materially promotes the drying action. It is then necessaryl to spread the prunes on drying trays, then to stack the trays on the loading platforms 25, then to transfer the load of platforms i-nto the driers, then to remove them and haul the same'to the storage bins, etc. Many dry- Ving plants are so arranged that the trays may be stacked on cars and the cars moved on tracks, but such an installation is naturally costly and is entirely eliminated in this instance as it is only necessary, to provide concrete or wooden runways for the trucks and platforms there employed. The operation will be as follows:v A number of trays -arestacked uponV a platform such las indicated at 25 (see Fig. 2). The trays are, of couiise, interspac'ed and loaded'with the fruitor other material to be dried. Different varieties of fruit,l vegetables, and other prod-H v ucts require varying drying temperatures,

and 4certain conditions of humidity. We will accordingly suppose that it is first desired tosubject a fruit to air havinga temperature of 110 F. and also that it`is desired to maintain a certain humidity content as far as the drying air is concerned.

If this is the case,rthe operator regulates the devices indicated at 11 and sets the same at 110 F. The devices 11 regluate` the theralso gradually absorbs the moisture liberated c by the material being dried and the humidity content of the air therefore gradually increases, and when the humidity content reaches a predetermined point the operator vWho watches the hygrometers through ,the

windows merely slightly opens the dampers 1-9. The exhaust blowers 18 are in continuous operation and as the exhaust pipes 16 are subjected to the suction thereof it is obvious that a small proportion of the air withinv thedrying'chamber will be exhausted or removed and will be discharged through the pipes 30 of the blower.` A slight vacuum is accordingly formed within the drying compartments and fresh air from the atmosphere Will automatically be drawn in through the main inlet pipe 15 and the verand mingle with the air circulated within the drying compartments. The fresh air admitJ ted yis of course dry and the humidity con- \tical inlet pipes 14, and as such will enter tent will gradually lower. The operator who is continuously watching will adjust the dampers l9,until a balance is maintainedg' that' is, just suilicient air is continuouslyexhausted to permit a sufficient amount/ of fresh air to continuously enter and thereby maintain the Ycirculating drying air at -an approximately constant nhumidity vcontent If it is desired to `increase or decrease ,the temperature of the air during the drying-operation, it is only necessary for the operator to regulate 'the devices indicated at`1'1 as these in turn regulate the thermostat valves 10 and thereby increase or decrease the flow of temperature through the radiators. An important feature in connection with the air control is that of preheating the in comin'g fresh air.' If a temperature of 110 F. is maintained within the dryer it is obvious that the exhausted air will discharge ai this temperature. The inlet air pipes surround the exhaust pipes and the incoming air is accordingly heated -both by condu/ction and convection. |llhis is of material importance as the general thermal eiiiciency of the plant is considerably increased and a 'proportion ate amount of fuely is saved as far as the l are also important as they permit ready removal and replacement of drying trays from time to time. The thermostatregulators 11 and the thermostat actuated valves are fully disclosed in my co-pending application entitled Driers filed June 11, 1923, Serial No. 644,541 andI a detailed description of their construction and operation is therefore thought unnecessary; The main novel feature of the present invention is the arrangement of exhaust and inlet pipes .together with the dampers 19 which regulate the flow of air through the preheater. The

dampers are exceedingly important as they materially increase the heat eiiiclency of the plant and furthermore provide a single controlv whereby the air exhausted and the air,

Having thus' described my invention, whatv I claim and desire to secure by Letters Patent is- 1. A drier of the character ldescribed comprising a housing having. a compartment formed therein, air heating means 1n the compartment, means for maintaining a constant circulation and iiow of air through the compartment and thel heating means, con-v centric air inlet and exhaust pipes connected with the compartment, whereby the air is exhausted and fresh air is admitted and heated by the exhaust air, suction means connected with theexhaust pipe to withdrawr air from the compartment by suction, Vand a single means controlling the volume of air exhausted'and thevolume of air which is preheated and admitted to the compartment.

2. A drier ofthe character describedvcom-l prising a housing having' al compartment formed there1n, a1r heating means 1n the compartment, means for malntalnmg a constant circulationand flow of air through the compartment and the heating' means, concentric air inlet and exhaust pipes connected with the compartment, whereby the air, is

Iexhausted and fresh air is admitted and heated by the exhaust air, suction means connected with the exhaust' ipeto Withdraw air from the compartment y suction, and a damper in the exhaust pipev controlling the volume of air exhausted'and the volume of air which is preheated and admitted to thev compartment. v

.-.ing-fromth'e main air pipe and'connected 3. drier of the character described comprising a housing, a partition in' the housing dividing it into two compartments, said partition having an opening formed in each end whereby communication'is maintained between the compartments, air heating .means in onel compartment, means for main- --taining a-constant circulation and flow of air through the heating means, the openings in the partition andthe respective compartments, an` air exhaust Ipipe in communication with the compartments, an air inletpipe also communicating*with the compartments said air inlet pipe lenclosingl the air exhaust pipe and forming an annular inletv passage wherein incoming air may be preheated by the exhausting air, a suc-tion blower connected with the -exhaust pipe and a damper in said pipe to regulate the volumes of air exhausted and admitted.-

- 4. A drier o-f the character 'described comprising a housing, a partition in theA housing dividing it into two compartments, said partition having an opening formed in each end whereby communication is maintained between vthe compartments, air heating means in one compartment, means for maintaining a constant circulation and flow of air through the heatingv means, Vthe openings in the partition and the, respective compart'ments, an air preheater, an airf exhaust p-ipe connected with the compartment and the preheaterto heat the same, an air inlet pipe connected with the preheater andthe compartment, means exerting an evacuating l effect onthe exhaust' pipe to remove air from the compartments andto circulate'said air through the' preheater, and means fo-r.

regulating the volume of air thus removed and for simultaneously admitting an equivalentv volume of preheated air to the compartments.

5. A drier 4of the character described comprising a plurality of drying compartments, a common air exhausting pipe, pi nleading therefrom `to each drying compartment, .a dam-per in each of said last named pipes,-

manually controlled means for opening and closingl any damper, and means for replacing the air exhausted and `for vpreheating the same by means of theexhaustingair when aldainper isf opened and air is. exhaust- 1 I 6'. A drier of the character described comprising a plurality ofv drying compartments, a main air exhaust-ing pipe, branch pipes leading therefrom tov each drying compartment, a' suction blower'conne'cted withthe main exhaust pipe, a damper in each branch pipe,.manually controlled meansifor opening .and closing any damper, a main air' inlet pipeenclosing the main exhaust'pi f and spaced-therefrom to form an airin et and preheating passage, branch air 'pipes leadwith each compartment said last named pipes enclosing the exhaust branch pipes and spaced therefrom to forma secondary air inlet and preheating passages, said main 5. and branch -air inlet and preheating pipes forming constant communication between theJexterlor atmosphere and the lnterlor of the respective compartments and adapted to automatically replace the air exhausted when the damper is opened and also auto- 10 matically maintaining atmospheric. pressure in each compartment.

Y GEORGE R. ANDERSON. 

